It has been recognized that there can be a droop in the output speed in a hydrostatic or hydromechanical transmission having a variable displacement pump supplying fluid to a fixed displacement motor when the fluid system pressure increases because of an increased load on the transmission. This droop results because an increase of pressure in the fluid system results in an increase in system flow leakage whereby the motor effectively operates with less fluid with the pump at a particular displacement. It is known to eliminate this speed droop by use of complex and costly electronic controls wherein the actual output speed of the transmission is detected and any deviation from the desired speed results in a modification of the displacement of the variable displacement pump.